Sliding ejector pad attachment for use with sliding bolster plate for presses

ABSTRACT

This disclosure relates to an ejector pad attachment for use with a sliding bolster plate of a press and permits a movable die member carried by a sliding bolster plate to have constantly associated therewith a supporting ejector pad while at the same time permitting the movable die member and ejector pad to move as is required during the operation of the press. The ejector pad is carried by the bolster plate for movement therewith and there is provided at the work station a platen assembly which is cooperable with the ejector pad to resiliently resist the displacement of the ejector pad and an associated die member during a work forming operation and thereafter return the movable die member and ejector pad to their original positions prior to the retraction of the bolster plate.

United States Patent Specht et al.

[ 1 Sept. 17, 1974 1 SLIDING EJECTOR PAD ATTACHMENT FOR USE WITH SLIDING BOLSTER PLATE FOR PRESSES [75] Inventors: Thomas F. Specht, Arlington Heights; Robert J. Babecki, Chicago, both of I11.

[73] Assignee: Union Special Corporation, Chicago,

Ill.

[22] Filed: June 27, 1973 [21] Appl. No.: 374,037

[52] US. Cl. 72/427 [51] Int. Cl B2ld 45/00 [58] Field of Search 72/427, 344, 345, 346;

[56] References Cited UNITED STATES PATENTS 3,283,551 11/1966 Kraft 72/427 Primary ExaminerCharles W. Lanham Assistant Examiner-Robert M. Rogers Attorney, Agent, or Firm-Diller, Brown, Ramik & Wight [5 7 ABSTRACT This disclosure relates to an ejector pad attachment for use with a sliding bolster plate of a press and permits a movable die member carried by a sliding bolster plate to have constantly associated therewith a supporting ejector pad while at the same time permitting the movable die member and ejector pad to move as is required during the operation of the press. The ejector pad is carried by the bolster plate for movement therewith and there is provided at the work station a platen assembly which is cooperable with the ejector pad to resiliently resist the displacement of the ejector pad and an associated die member during a work forming operation and thereafter return the movable die member and ejector pad to their original positions prior to the retraction of the bolster plate.

18 Claims, 5 Drawing Figures SLIDING EJECTOR PAD ATTACHMENT FOR USE WITH SLIDING BOLSTER PLATE FOR PRESSES This invention relates in general to new and useful improvements in press assemblies of the punch press and like type, and more particularly to a novel ejector pad attachment for such presses.

It is well known in the construction of dies for presses to construct the base die with a movable part having means resistingly urging the same to a normal position and wherein after the press has performed its operation, the movable die part is urged back to its normal position and at least partially ejects the worked upon workpiece from the base die. Such a die arrangement is disclosed, for example, in the patent to Irmis, US. Pat. No. 1,915,531 granted June 27, 1933. It is to be noted that in accordance with this patent, the ejector mechanism is part of the base die and that a suitable opening is provided both in the bolster plate and the press bed for the dependent components of the die.

It will be readily apparent from the foregoing Irmis patent that if the bolster plate were of the sliding type which moves the base die from a loading position to its work position, it would be necessary for the ejector mechanism to move with the base die and the bolster plate with the result that the opening in the bed of the press would have to be elongated thus requiring a special press design.

A further disadvantage of the arrangement of the Irmis patent is that each and every base die which has an ejector mechanism incorporated therein requires the specific ejector structure. This is because the ejector structure is part of the base die and not part of the press or an attachment for the press.

It is also to be understood that normally when a press is converted to utilize a sliding bolster plate, there is mounted on the bed of the press a bolster plate base. The bolster plate is seated on such bolster plate base and accordingly, the bolster plate base would have to be specially constructed to have a slot for the passage of the ejector components and thus weakened.

In accordance with this invention, it is proposed to provide an ejector pad attachment particularly adapted to be utilized in conjunction with a sliding bolster plate. The ejector pad attachment includes a platen assembly which may be conveniently bolted to the underside of the bolster plate base in a fixed position aligned with the work position of the press with the platen assembly including a platen which is positioned within an opening in the bolster plate base. The sliding bolster plate is provided with a similar opening which becomes aligned with the opening in the bolster plate base when the bolster plate is in the work position. The opening in the bolster plate has freely positioned therein an ejector pad which in the loading position of the bolster plate is seated on the bolster plate base and which slides along the bolster plate base as the bolster plate is advanced and retracted. In the work position of the bolster plate, the ejector pad seats upon the platen of the platen assembly and when the movable die member is depressed during a work operation, the ejector pad is forced partially through the associated opening in the bolster plate, pressing the platen through the associated opening in the bolster plate base and overcoming the resistance to the movement of the platen. As soon as the movable die begins to retract, the platen is urged back to its normal position, forcing the ejector plate to its normal position which, in turn, forces the movable die member to its normal position.

From the foregoing, it will be readily apparent that the platen assembly may be readily attached to the bolster plate base as an accessory and that the ejector pad is the only added element which moves with the bolster plate. Since the platen assembly is self-contained, once the ejector pad is removed from the bolster plate, the ejector assembly is rendered inoperative.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings:

In the drawings:

FIG. 1 is a fragmentary horizontal sectional view taken through a press and shows in plan the sliding bolster plate assembly and the base die carried by the bolster plate.

FIG. 2 is a transverse vertical sectional view taken along the line 2-2 of FIG. 1 and shows specifically the relationship of the sliding bolster plate assembly with respect to the press bed and the details of the base die and ejector pad attachment carried by the bolster plate assembly.

FIG. 3 is a fragmentary longitudinal vertical sectional view taken along the line 3-3 of FIG. 1 and shows further the details of the bolster plate assembly and ejector pad attachment.

FIG. 4 is a fragmentary plan view of the bolster plate assembly with the bolster plate in the work position thereof and shows further the details of the ejector pad attachment.

FIG. 5 is an enlarged exploded perspective view of the components of the ejector pad attachment.

Referring now to the'drawings in detail, it will be seen that there is illustrated in FIG. 1 a portion of a conventional punch press bed 10 which has mounted thereon a sliding bolster plate assembly, generally identified by the numeral 11. Such a bolster plate assembly may be of the type disclosed in the patent to Ferris, et al., US. Pat. No. 3,446,l06,granted May 27, 1969, and operated in the manner specifically disclosed in that patent.

The bolster plate assembly 11 includes a bolster plate base 12 which is fixedly secured on the bed 10 by means of suitable fasteners 13. The bolster plate base 12 includes side guides 14 along opposite edges thereof, the side guides 14 being preferably secured to the bolster plate base 12 by means of suitable fasteners 15.

The bolster plate assembly 11 further includes a sliding bolster plate 16 which overlies the bolster plate base 12 between the guides 14 and is supported and guided thereby for reciprocatory movement between an advanced loading position (not shown) and a retracted work position shown in FIG. 1. Reciprocation of the bolster plate 16 is preferably effected by means of a double acting cylinder 17 which is connected to the bolster plate 16 by means of a suitable coupling 18.

The lower portion or base die 20 of a forming die set is releaseably secured by bolts 21 to the bolster plate 16 for movement therewith. It is to be understood that the bolster plate 16 will be provided with a plurality of sets of threaded bores 22 for receiving the bolts 21 so that various base dies may be mounted on the bolster plate 16 for movement therewith.

The base die 20 includes a base member 23 which is directly secured to the bolster plate 16 by the bolts 21. Overlying the base plate 23 and secured thereto is a forming die 24, the forming die 24 being secured to the base plate 23 by means of screws 25. The forming die 24 includes a die member 26 and an overlying locating plate 27. The die member 26 is provided with a recess 28 in which there is mounted for movement a movable die member 30. The movable die member 30 has threadedly engaged in the lower portion thereof depending ejector pins 31 which pass through aligned bores in the die member 26 and the base plate 23.

It is to be particularly noted here that the ejector pins 31 are so related with respect to the movable die member 30 and the upper surface of the bolster plate 16 that when the movable die member 30 is in its proper uppermost position, the lower ends of the ejector pins 31 are substantially flush with the upper surface of the bolster plate 16.

At this time it is further pointed out that the press of which the bed is a part will be provided with a suitable reciprocating ram (not shown) and that such ram will be provided with an upper half (not shown) of the die set which will cooperate with the lower half or base portion of the die set. Except for the fact that the lower die half 20 includes the movable die member 30 which is provided with the ejector pins 31, the construction of the die set is in no way a part of this invention.

As is clearly disclosed in the above-identified Irmis patent, customarily the lower die half 20 would have associated therewith a platen assembly operable on the ejector pins 31 if the die half 20 were mounted on a fixed bolster plate. However, inasmuch as the bolster plate 16 is a sliding bolster plate, it is quite apparent that such a platen assembly cannot be incorporated as part of the bottom die half 20.

In accordance with this invention, there is provided as an attachment for a sliding bolster plate assembly of the type disclosed in the aforementioned Ferris, et al. U.S. Pat. No. 3,446,106 a platen assembly which is generally identified by the numeral 32. The plate assembly 32, as best illustrated in FIGS. 2 and 5 include a channel shaped support block 33 which is fixedly secured to the underside of the bolster plate base 12 in alignment with an opening 34 formed therein by means of suitable bolts 35. The block 33 is provided with a plurality of guide bores 36 through which sliding bolts or pins 37 extend, the sliding bolts 37 having upper ends which are threadedly engaged into internally threaded bores 38 formed in a platen 40. The platen 40 is of a size to generally fill the opening 34 but is free to move through the opening. The lower ends of the sliding bolts 37 are provided with heads 41 which are engagable with the underside of the block 33 and serve to define the uppermost position of the platen 40. At this time it is pointed out that the block 33 is positioned within a customary opening 42 formed in the bed 10.

The platen assembly 32 also includes an elongated rod 43 which has a threaded upper end portion 44 engaged in a centrally located threaded bore 45 in the block 33. The rod 43 depends from the block 33 and has positioned on the upper portion thereof for relative sliding movement a washer 46 which engages the bolt heads 41. The washer 46 is spring urged upwardly by means of a spring 47 carried by the rod 43 and restrained against downward movement by a washer 48 retained in an adjusted position by lock nuts 50 threaded on a threaded lower portion 51 of the rod 43. It is to be understood that the spring loaded washer 46 normally serves to maintain the platen 40 in the position illustrated in FIG. 2.

It will be readily apparent that the platen assembly 32 is fixedly mounted on the bolster plate base 12 and thus does not move with the bolster plate 16. It will also be apparent that inasmuch as the uppermost position of the platen 40 is adjustable, the platen 40 can be positioned so that it in no way interferes with the movement of the bolster plate 16. It is further to be understood that the platen 40 is positioned in alignment with the ram (not shown) of the press.

In order that the platen assembly 32 may cooperate with the movable die member 30, the bolster plate 16 is provided with an opening 52 which corresponds with the opening 34 of the bolster plate base 12 and which is aligned therewith when the bolster plate 16 is in its work position. An ejector pad 53 is loosely disposed within the bolster plate opening 52 and is free to move vertically therethrough when the openings 34 and 52 are aligned.

The ejector pad 53 is of a thickness substantially identical to and no greater than the thickness of the bolster plate 16. When the bolster plate 16 is in its loading position, the ejector pad 53 rests upon the bolster plate base 12 and thus, by engaging the lower ends of the ejector pins 31, maintains the movable die member 30 in its uppermost position of FIG. 2.

When the bolster plate 16 is advanced to the work position thereof, the ejector pad 53 moves therewith, sliding on the surface of the bolster plate base 12 until it reaches the opening 34 at which time it moves into overlying relation with respect to the platen 40 and is supported thereby. It will be readily apparent from FIG. 2 that when the bolster plate 16 is in its work posi tion, the ejector pad 53 is supported solely by the, platen 40 and is free to move downwardly against the resistance of the spring 47 thus permitting the movable die member 30 to move downwardly during a work forming operation. Further, the spring 47, in returning the platen 40 to its normal position, will move the ejector pad 53 back up to its normal position and thus through the ejector pins 31 move the movable die member 30 back to its normal position. The ejector pad 53 is now ready to move together with the bolster plate 16 off of the platen 40 and back onto the surface of the bolster plate base 12.

Referring now to FIG. 3 in particular, it will be seen that the ejector pad 53 has an undersurface which is bevelled as at 54, on opposite sides thereof transversely of the direction of movement of the bolster plate 16. The bevelling of the undersurface of the ejector pad 53 permits the ejector pad 53 to ride off of the bolster plate base 12 onto the platen 40 and back onto the bolster plate base even though the upper surfaces of the two are not perfectly aligned. In practice, the sliding bolts 37 are adjusted so that the upper surface of the platen 40 is approximately 0.003 inch below the surface of the bolster plate base 12. In this way wedging of the ejector pad 53 between the platen 40 and the base member 23 is prevented.

As is best illustrated in FIG. 5, the ejector pad 53 is provided with a threaded hole 55 for reception of a threaded member. Such a member may be readily engaged with the ejector pad 53 to facilitate the removal thereof from the bolster plate 16 after the lower die half has been removed.

At this time it is pointed out that although the platen has been illustrated as being resistingly supported by a spring, it is to be understood that the means for urging the platen to its uppermost position and resisting the downward movement thereof could be in the form of a rubber support pad, a fluid cylinder or other equivalent devices.

Although only a preferred embodiment of the ejector pad assembly has been specifically illustrated and described herein, it is to be understood that minor variations may be made therein without departing from the spirit and scope of the invention, as defined by the appended claims.

We claim:

1. A press assembly comprising a press bed, a sliding bolster plate mounted on said press bed for reciprocatory movement between a loading position and a work position, an ejector pad loosely carried by said bolster plate for movement therewith, and a platen assembly fixedly mounted at said work position for underlying said ejector pad and cooperating therewith during a press operation.

2. The press assembly of claim 1 wherein a bolster plate base supports said bolster plate and underlies said bolster plate in all positions thereof, said bolster plate base supporting said ejector pad in all positions thereof except at said work position.

3. The press assembly of claim 2 wherein said bolster plate base has an opening therethrough at said work position aligned with said ejector pad, and said platen assembly is partially mounted in said bolster plate base opening and supports said ejector pad in the work position of said bolster plate.

4. The press assembly of claim 3 wherein said platen assembly is fixedly carried by said bolster plate base.

5. The press assembly of claim 3 wherein said platen assembly includes a platen positioned within said bolster plate base opening and having a support surface disposed generally coplanar with a surface of said bolster plate support.

6. The press assembly of claim 5 wherein said platen assembly includes means resistingly urging said platen towards generally coplanar position, and step means limiting movement of said platen towards said generally coplanar position.

7. The press assembly of claim 3 together with a die set secured to said bolster plate in alignment with said ejector pad, said die set including a movable die member and means supporting said die member on said ejector pad for positioning thereby.

8. A sliding bolster plate assembly comprising a bolster plate base and a bolster plate mounted on said bolster plate base for sliding movement between a loading position and a work position, said bolster plate having means predetermining the position of a die set to be mounted thereon, an opening through said bolster plate in alignment with said die set predetermined position, an ejector pad loosely positioned in bolster plate opening for movement therethrough and normally seated on said bolster plate support, and a platen assembly fixedly mounted on said bolster plate base at said work position for supportingly underlying said ejector pad cooperating therewith during a press operation.

9. The sliding bolster plate assembly of claim 8 wherein said bolster plate base has an opening therethrough at said work position aligned with said ejector pad, and said platen assembly is partially mounted in said bolster plate base opening and supports said ejector pad in the work position of said bolster plate.

10. The sliding bolster plate assembly of claim 9 wherein said platen assembly includes a platen positioned within said bolster plate base opening and having a support surface disposed generally coplanar with a surface of said bolster plate support.

11. The sliding bolster plate assembly of claim 10 wherein said platen assembly includes means resistingly urging said platen towards generally coplanar position, and step means limiting movement of said platen to wards said generally coplanar position.

12. The bolster plate assembly of claim 10 wherein.

said ejector pad has a partially relieved surface opposing said bolster plate base for facilitating movement of said ejector pad onto and off of said bolster plate base relative to said platen.

13. A bolster plate assembly comprising a slidable bolster plate having an opening therethrough, and an ejector pad freely positioned in said opening for movement relative to said bolster pad generally through said opening.

14. The bolster plate assembly of claim 13 wherein said bolster plate and said ejector pad are substantially the same thickness.

15. An ejector pad attachment for a press bolster plate assembly of the type including a sliding bolster plate, said ejector pad attachment comprising a support, a platen carried by said support for predetermined movement relative thereto, cooperating means between said support and said platen for resistingly urging said platen to a predetermined position relative to said support, and an ejector pad loosely seated on said platen for sliding movement thereof.

16. The ejector pad attachment of claim 15 wherein said ejector pad is adapted for movement with an associated bolster pad off and onto said platen and has a platen engageable surface being relieved to facilitate such movement.

17. The ejector pad attachment of claim 15 wherein said ejector pad has means for retriving the same from a bolster plate.

18. A new article of manufacture comprising an ejector pad positionable within a sliding bolster plate for movement therewith into position between a fixed platen assembly and a movable die member for temporarily coupling the platen assembly to the die member in supporting relation.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,835,691 DATED September 17, 1974 INVENTOR(S) Thomas F. Specht and Robert J. Babecki It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, lines 5, 7 and 14, read "base plate 23 as base member 23 Column 3, line 44, read "The plate assembly" as The platen assembly Claim 13, line 32, read "bolster pad" as bolster plate'-;

Claim 16, line 48, read "bolster pad" as bolster plate In the drawings:

The threaded hole 55 in the ejector pad 53 of Figure 5 should be viewed as being present in Figures 2, 3 and 4;

In Figure 5, read numeral 32 as referring to the platen assembly, as in Figures 2 and 3.

Signal and Scaled this second Day of W197:

[SEAL] A ttesl:

RUTH C. MASON C. IAISIIALL DANN Arresting Officer (om missiuntr ofPat ms and Trademarks 

1. A press assembly comprising a press bed, a sliding bolster plate mounted on said press bed for reciprocatory movement between a loading position and a work positioN, an ejector pad loosely carried by said bolster plate for movement therewith, and a platen assembly fixedly mounted at said work position for underlying said ejector pad and cooperating therewith during a press operation.
 2. The press assembly of claim 1 wherein a bolster plate base supports said bolster plate and underlies said bolster plate in all positions thereof, said bolster plate base supporting said ejector pad in all positions thereof except at said work position.
 3. The press assembly of claim 2 wherein said bolster plate base has an opening therethrough at said work position aligned with said ejector pad, and said platen assembly is partially mounted in said bolster plate base opening and supports said ejector pad in the work position of said bolster plate.
 4. The press assembly of claim 3 wherein said platen assembly is fixedly carried by said bolster plate base.
 5. The press assembly of claim 3 wherein said platen assembly includes a platen positioned within said bolster plate base opening and having a support surface disposed generally coplanar with a surface of said bolster plate support.
 6. The press assembly of claim 5 wherein said platen assembly includes means resistingly urging said platen towards generally coplanar position, and step means limiting movement of said platen towards said generally coplanar position.
 7. The press assembly of claim 3 together with a die set secured to said bolster plate in alignment with said ejector pad, said die set including a movable die member and means supporting said die member on said ejector pad for positioning thereby.
 8. A sliding bolster plate assembly comprising a bolster plate base and a bolster plate mounted on said bolster plate base for sliding movement between a loading position and a work position, said bolster plate having means predetermining the position of a die set to be mounted thereon, an opening through said bolster plate in alignment with said die set predetermined position, an ejector pad loosely positioned in bolster plate opening for movement therethrough and normally seated on said bolster plate support, and a platen assembly fixedly mounted on said bolster plate base at said work position for supportingly underlying said ejector pad cooperating therewith during a press operation.
 9. The sliding bolster plate assembly of claim 8 wherein said bolster plate base has an opening therethrough at said work position aligned with said ejector pad, and said platen assembly is partially mounted in said bolster plate base opening and supports said ejector pad in the work position of said bolster plate.
 10. The sliding bolster plate assembly of claim 9 wherein said platen assembly includes a platen positioned within said bolster plate base opening and having a support surface disposed generally coplanar with a surface of said bolster plate support.
 11. The sliding bolster plate assembly of claim 10 wherein said platen assembly includes means resistingly urging said platen towards generally coplanar position, and step means limiting movement of said platen towards said generally coplanar position.
 12. The bolster plate assembly of claim 10 wherein said ejector pad has a partially relieved surface opposing said bolster plate base for facilitating movement of said ejector pad onto and off of said bolster plate base relative to said platen.
 13. A bolster plate assembly comprising a slidable bolster plate having an opening therethrough, and an ejector pad freely positioned in said opening for movement relative to said bolster pad generally through said opening.
 14. The bolster plate assembly of claim 13 wherein said bolster plate and said ejector pad are substantially the same thickness.
 15. An ejector pad attachment for a press bolster plate assembly of the type including a sliding bolster plate, said ejector pad attachment comprising a support, a platen carried by said support for predetermined movement relative thereto, cooperating means between said support and said platEn for resistingly urging said platen to a predetermined position relative to said support, and an ejector pad loosely seated on said platen for sliding movement thereof.
 16. The ejector pad attachment of claim 15 wherein said ejector pad is adapted for movement with an associated bolster pad off and onto said platen and has a platen engageable surface being relieved to facilitate such movement.
 17. The ejector pad attachment of claim 15 wherein said ejector pad has means for retriving the same from a bolster plate.
 18. A new article of manufacture comprising an ejector pad positionable within a sliding bolster plate for movement therewith into position between a fixed platen assembly and a movable die member for temporarily coupling the platen assembly to the die member in supporting relation. 